DNA SEQUENCING ENZYMES

Abstract: There are provided variant family B DNA polymerases having no 3'}5' exonuclease activity. These variant polymerases have utility as DNA sequencing polymerases. Methods for DNA sequencing with family B DNA polymerases and chain-terminating nucleotides not previously used for sequencing have been developed. The methods disclosed involve the use of family B DNA polymerases not known heretofore to have utility in DNA sequencing, such as variant or wild type forms of phage T4 DNA polymerase or Escherichia coli DNA polymerase II, with novel combinations of deoxynucleotides and chain-terminating nucleotides.

Description: DNA SEQUENCING ENZYMES BACKGROUND OF THE INVENTION The present invention relates to modifications of the DNA sequencing method developed by F. Sanger (Sanger, F., Nicklen, S., Coulson, A. R. (1977) Proc. Natl. Acac. Sci. U.S.A. 74, 5463-5467) as well as to novel enzymes which can be used for DNA sequencing. The Sanger sequencing method is based on in vitro DNA synthesis reactions in the presence of a primed DNA template, 2'- deoxyribonucleoside triphosphates (dNTPs, see Fig. 1), and 2', 3'- dideoxyribonucleoside triphosphates (ddNTPs, Fig. 1). The latter, when incorporated by a DNA polymerase into a polynucleotide chain, terminate further chain elongation. The DNA products are thus a series of polynucleotide chains complementary to the template and terminated with specific dideoxynucleotides. The DNA sequencing products can be separated by size and the pattern of the products gives the DNA sequence. In principle, DNA polymerases from a variety of organisms and a variety of chain-terminating nucleotides should be useful to sequence DNA. In practice, few DNA polymerases and chain-terminating nucleotides have been found to be suitable for this purpose. As an example of a DNA sequencing polymerase, the development of bacteriophage T7 DNA polymerase, Sequenace™, will be reviewed (Tabor, S., and Richardson, C. C. (1990) J. Biol. Chem. 265, 8322-8328). In order to obtain an unambiguous DNA sequence it is necessary that the majority of sequencing products terminate with a dideoxynucleotide and that all the sequencing products are represented equally. Two phage T7 DNA polymerase activities degrade DNA sequencing products and, thus, these activities must be eliminated in order to prevent degradation of dideoxynucleotide-terminated sequencing products. One activity, 3'→5' exonuclease activity, was removed by constructing an exonuclease deficient variant of T7 DNA polymerase. T7 DNA polymerase also has pyrophosphorolytic activity which can degrade the sequencing products. Pyrophosphatase was added to degrade pyrophosphate produced in the DNA sequencing reactions; without pyrophosphate, there is no pyrophosphorolysis. A further refinement of the sequencing reactions was to use Mn 2+ in place of Mg 2+ which resulted in a more equal distribution of reaction products. Although this brief review of the development of T7 DNA polymerase into a sequencing polymerase is a simplification, the review illustrates the point that modification of a natural DNA polymerase as well as development of reaction conditions is required in order to obtain high quality DNA sequence information using the chain-terminating sequencing method. Optimal DNA sequencing conditions using the chain-terminating method have not yet been achieved. Ambiguous sequencing information is still observed which necessitates determining the DNA sequence of both DNA strands. Also, the use of Mn 2+ in place of Mg 2+ increases the amount of DNA template required for sequencing reactions. Thus it would be advantageous to develop novel methods that would improve or complement existing sequencing procedures. The wild type T4 DNA polymerase gene has been cloned and the protein product expressed (Lin, T.-C, Rush, J. R., Spicer, E. K., and Konigsberg, W. H. (1987) Proc. Natl. Acad. Sci. U.S.A. 84, 7000-7004; U.S. Patent 4,935,361 to Lin et al.) and E. coli DNA polymerase II has been cloned and expressed (Bonner, C. A., Hays, S., McEntee, K., and Goodman, M. F. (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 7663-7667). Standard oligonucleotide-directed mutagenesis techniques have been used to construct novel forms of T4 DNA polymerase and E-. coli DNA polymerase II. Thus, the means exist to economically prepare large quantities of wild type and variant T4 DNA polymerase and E. coli DNA polymerase II. Another aspect of the invention is to use genetic analysis to identify DNA polymerases with properties useful for DNA sequencing. T4 DNA polymerase is one of the most extensively genetically characterized DNA polymerases (Reha- Krantz, L. J. (1993) In Molecular Biology of Bacteriophage T4, ed. Karam J., American Association for Microbiology, in press); hence, some mutant DNA polymerases already identified may have properties useful for DNA sequencing and new mutants can be isolated directly. A method to isolate novel T4 DNA polymerases with useful DNA sequencing properties would be of additional utility. SUMMARY OF THE INVENTION In accordance with aspect of the invention, there are provided novel enzymes which may be used as DNA sequencing polymerases. These enzymes result from genetic mutations of family B DNA polymerases. These mutations eliminate the 3'→5' exonuclease activity of these novel family B DNA polymerases. In accordance with another aspect of the invention, there are provided methods that enable phage T4 DNA polymerase and E. coli DNA polymerase II to be used as DNA sequencing polymerases. DNA polymerase modifications that convert phage T4 DNA polymerase and E. coli DNA polymerase II into DNA sequencing polymerases can also be used to similarly modify DNA polymerases having protein sequence homology with these two polymerases. DNA polymerases with protein sequence similarities to T4 DNA polymerase and E. coli DNA polymerase II include, but are not limited to, a group of DNA polymerases that are called Family B DNA polymerases (Braithwaite, D. K. and Ito, J. (1993) Nucl. Acids Res. 21, 787-802). Of particular relevance are the DNA polymerases from phages T2 and T6 which have extensive protein sequence homology to T4 DNA polymerase. Another extension of methods described here is that DNA polymerases with functional similarities to T4 DNA polymerase and E. coli DNA polymerase II may also be used to produce DNA sequence information with the chain-terminating nucleotides and methods disclosed hereinafter. In accordance with another aspect of this invention there is provided a method to identify DNA polymerase modifications, having one or more specific amino acid substitutions in the polymerase protein sequence, that improve a given DNA polymerase in terms of DNA sequencing applications. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 depicts the structure of standard nucleotides and nucleotide analogs useful in the practice of the invention. Fig. 2 depicts DNA sequencing gels which resulted from the use of variant E. coli DNA polymerase II and T4 DNA polymerase. Fig. 3 depicts a DNA sequencing gel in which dATP is used at very- low concentrations compared to the other standard nucleotides. Fig. 4 depicts primer extension past a template abasic site (X) by wild- type and mutant T4 DNA polymerases. DETAILED DESCRIPTION OF THE INVENTION An aspect of the invention, namely to identify modified DNA polymerases with new properties that improve the ability of the modified DNA polymerases to carry out DNA sequencing reactions, is achieved by the design of a new genetic selection strategy that identifies modified DNA polymerases with superior DNA replication activities. The new genetic selection strategy has been designed around the T4 DNA polymerase. T4 DNA polymerase (SEQ ID NO: 3 and 4) and E. coli DNA polymerase II (SEQ ID NO: 5 and 6), which have heretofore been unable to be used as sequencing polymerases, can be used as DNA sequencing polymerases in Sanger- type reactions if non-standard or novel combinations of chain-terminating nucleotides are used. Further to this discovery is the finding that inactivation of 3'→5' exonuclease activity in T4 DNA polymerase and E. coli DNA polymerase II improves the quality of the DNA sequence information obtained. In a further aspect, additional polymerase modifications have been discovered, which when combined with other modifications that reduce 3'→5' exonuclease activity, have the potential to produce a multiply modified DNA polymerase with advantageous DNA sequencing properties. Due to extensive sequence homology with T4 DNA polymerase, DNA polymerases such as phages T2 (SEQ ID NO: 1 and 2) and T6 DNA polymerases are particularly suitable in the application of the methods of the invention. T4 DNA polymerase and E. coli DNA polymerase II can be used as effective DNA sequencing polymerases if the arabinonucleotides (Fig. 1), araUTP and araCTP, are used in place of the standard chain-terminating nucleotides ddTTP and ddCTP. The standard purine dideoxynucleotides (Fig. 1), ddATP and ddGTP, are effective chain-terminating nucleotides for T4 DNA polymerase and E. coli DNA polymerase II. DNA sequencing reactions for T4 DNA polymerase and E. coli DNA polymerase II differ from standard DNA sequencing reactions in that a novel combination of chain-terminating nucleotides is used. Although in principle any chain-terminating nucleotide may be used, DNA polymerases differ markedly in their ability to incorporate these nucleotides into the DNA chain. For T4 DNA polymerase and E. coli DNA polymerase II, the low incorporation of ddTTP and ddCTP by these enzymes have prevented the use of these standard chain-terminating nucleotides in sequencing protocols. The discovery that alternative chain-terminating arabinonucleotides, araCTP and araUTP, can be incorporated relatively efficiently by T4 DNA polymerase and E. coli DNA polymerase II enables these DNA polymerases to be used as sequencing polymerases. The DNA sequencing method that uses reactions with the novel combinations of chain-terminating nucleotides - araCTP, araUTP, ddATP and ddGTP, is described, hereinbelow, in Method I. A further discovery is that inactivation or significant reduction of the 3'→5' exonuclease activity of T4 DNA polymerase and Ε. coli DNA polymerase II enhances the quality of DNA sequence information obtained using the Method I sequencing reactions. T4 DNA polymerase 3'→5' exonuclease activity can be significantly reduced by an amino acid substitution including, but not limited to, one or more of the following amino acid substitutions in the enzyme: D112A + Ε114A, D219A and D324A. In the above nomenclature which is used herein throughout, the single letter code for amino acids is used. The numbers flanked by the single letter codes for amino acids are the codon numbers. For example, D112A + E114A indicates an alanine (A) substitution for aspartate (D) at codon position 112. D112A + E114A indicates two amino acid substitutions in the modified DNA polymerase. To achieve these variants the following mutations were employed: for D112A the A nucleotide at position 334 is replaced with a C nucleotide thereby effecting a change of the D amino acid to an A amino acid, as is known to one of ordinary skill in the art other nucleotide changes are capable of effecting the same change; for E114A the A nucleotide at position 340 is replaced with a C nucleotide, as is known other nucleotide changes can effect the same amino acid change; for D219A the A and C nucleotides at position 655 and 656, respectively, are replaced with a C and a G nucleotide, respectively, as is known other nucleotide changes can effect the same amino acid change; and for D324A the A nucleotide at position 970 is replaced with a C nucleotide, as is known other nucleotide changes can effect the same amino acid change. E. coli DNA polymerase II 3'→5' exonuclease activity can be significantly reduced by an amino acid substitution including, but not limited to, the following amino acid substitutions: D156A + E158A. To achieve these variants the following mutations were employed: for D156A the A nucleotide at position 467 is replaced with a C nucleotide, as is known other nucleotide changes can effect the same amino acid change; for E158A the A nucleotide at position 473 is replaced with a C nucleotide, as is known other nucleotide changes can effect the same amino acid change. Construction of 3'→5' exonuclease deficient variants of T4 DNA polymerase and E. coli DNA polymerase II is achieved by standard oligonucleotide mutagenesis procedures (for example, Kunkle, T.A., Roberts, J.D. and Zakour, R.A. (1987) Method. Enz. 154, 367-382). Another aspect of the invention may be achieved by using chain- terminating nucleotides that are not used in standard DNA sequencing reactions. T4 DNA polymerase and E. coli DNA polymerase II may also be used as effective DNA sequencing polymerases if 3'amino-2',3'-dideoxyribonucleotides (3'- NH 2 dNTPs) (Fig. 1) are used in place of the standard ddNTPs. This sequencing method is described herein below in Method II. Unmodified (wild type) T4 DNA polymerase and 3'→5' exonuclease deficient variants can be used in Method II reactions; the 3'→5' exonuclease deficient variant of E. coli DNA polymerase II has also been successfully used in Method II reactions. The 3'→5' exonuclease deficient form of T4 DNA polymerase can also be used to produce DNA sequence information without nucleotide analogs if the concentration of one of the four standard dNTPs is very low. For example, if the concentrations of dGTP, dCTP and dTTP are at 100 μM and the concentration of dATP is at 0.1 μM to 1 μM then sequencing products are observed that terminate one position before dATP is required for incorporation. With parallel reactions, each with one dNTP present at low concentration and the other three dNTPs present at high concentrations, the DNA sequence can be determined. This sequencing method is referred to hereinafter as Method III. The third objective, namely to identify variant or modified DNA polymerases with new properties that enable the polymerases to have enhanced sequencing properties, has been achieved by designing a new strategy to select for novel DNA polymerases. The new strategy, a type of genetic selection, was developed for phage T4. The basic strategy begins with a phage T4 strain that has one or more mutations in the DNA polymerase gene which result in a variant (mutant) DNA polymerase which is partially defective in some aspect of DNA replication. Several types of DNA polymerase modifications can reduce the ability of DNA polymerase to replicate DNA efficiently. For example, alterations in the ability of the DNA polymerase to bind DNA template or dNTPs or in the ability of the DNA polymerase to translocate along the DNA template will reduce DNA replication efficiency. For phage T4, DNA polymerase mutants with reduced DNA replication activity can be readily identified. Phage T4 strains with mutant DNA polymerases that are partially defective in DNA replication cannot synthesize DNA if the bacterial host used in the infection contains the optAl mutation. In other words, the E. coli optAl host restricts growth of T4 strains with mutant DNA polymerases defective in DNA replication activity. The basis of the restriction observed for the E. coli optAl strain is that increased amounts of an enzyme that degrades dGTP is produced (Wurgler, S. S., and Richardson, C. C. (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 2740-2744). Thus, phage T4 strains with variant DNA polymerases with reduced DNA replication activity cannot replicate DNA and produce phage progeny if the nucleotide pools, especially dGTP, are reduced. In terms of development of a genetic selection strategy, conditions have been established which can be used to identify DNA replication defective DNA polymerases as well as to restrict production of progeny from phages with such defective DNA polymerases, namely the restricted production of phage progeny in infections of the E. coli optAl bacterial host. These conditions, described hereinbelow, enable the selection of further modified (mutated) DNA polymerases with superior DNA replication ability. If the variant DNA polymerases with reduced DNA replication activity are further modified, for example by one or more additional amino acid substitutions, it may be that additional mutations/amino acid substitutions correct or compensate for the initial defect in DNA replication activity. Such further modified DNA polymerases will now be able to replicate DNA in the E coli optAl host and phage progeny will be produced. Thus, detection of phage progeny on the E. coli optAl host in infections with phage formerly restricted from producing progeny on this host allows for the selection of multiply mutant DNA polymerases that have the starting mutation (amino acid substitutions that decrease DNA replication activity) plus one or more new mutations that encode additional amino acid substitutions that correct or compensate for the starting DNA replication defect. The new correcting or compensating mutations (also called suppressor mutations in genetic terminology) can be identified by sequencing the phage DNA polymerase gene using standard procedures (McPheeters, D.S., Christensen, A., Young, E.T., Stormo, G., and Gold, L. (1986) Nucleic Acid Res. 14, 5813-5826; Reha-Krantz, L.J. (1988) J. Mol. Biol. 202, 711-724). The new mutations can be introduced into the phage T4 DNA polymerase gene or into T4 DNA polymerase expression vectors for further study. In contrast to the starting phage T4 DNA polymerases with reduced DNA replication ability, the new variant DNA polymerases have superior DNA replication ability because these variant DNA polymerases were selected on the basis of their ability to overcome, compensate or correct defects in variant DNA polymerase with reduced DNA replication activity. The genetic strategy to identify variant DNA polymerases with superior DNA replication abilities is highly sensitive as a single phage with the above described properties can be selected from a population of 10 8 to IO 9 phage. Further to the invention, variant DNA polymerases with superior DNA replication activity have properties advantageous for DNA sequencing polymerase, such as enhanced primer extension which produces a more uniform distribution of sequencing products and enhanced DNA replication in template regions that may block or hinder replication by unmodified DNA polymerases. T4 DNA polymerase variants with superior DNA replication ability are predicted to improve the quality of DNA sequence information produced by Methods I, II, and III. The genetic selection strategy described here for the detection of variant DNA polymerases with superior DNA replication ability can be applied to the DNA polymerases of other organisms if such defective DNA polymerases can be identified and if variants with correcting or compensating mutations can be selected. DNA Sequencing Method I. T4 DNA polymerase with significantly reduced 3'→5' exonuclease activity, such as variant forms with either D112A + E114A, D219A, or D324A amino acid substitutions, and E. coli DNA polymerase II with significantly reduced 3'→5' exonuclease activity, such as the variant form with D156A + E158A amino acid substitutions, can be used as DNA sequencing polymerases with the following set of chain-terminating nucleotides: ddATP, ddGTP, araCTP, and araUTP (Fig. 1). Figure 2 shows photographs of three DNA sequencing gels. DNA sequencing patterns obtained with Method I are in panels A and B, lanes 1-4, and panel C. Panel A shows DNA sequencing reactions with the exonuclease deficient variant of E. coli DNA polymerase II. The reaction with ddGTP is in lane 1, the reaction with ddATP is in lane 2, the reaction with araCTP is in lane 3, and the reaction with araUTP is in lane 4. Panel B shows DNA sequencing reactions with the exonuclease deficient form of bacteriophage T4 DNA polymerase. Again, lane I has reactions with ddGTP, lane 2 has ddATP, lane 3 has araCTP, and lane 4 has araUTP. The reactions in panels A and B have Mg 2+ as the divalent metal cation. Sequencing patters are also obtained with Mn 2+ in place of Mg 2+ . Method I reactions with Mn 2+ with the exonuclease deficient form of E. coli DNA polymerase II are shown on the left side of panel C, lanes 1-4; reactions with the exonuclease deficient form of T4 DNA polymerase are shown on the right side of panel C, lanes 1-4. Panel C, lanes 1-4 contain reactions with ddGTP (lane 1), ddATP (lane 2), araCTP (lane 3), and araUTP (lane 4). DNA Sequencing Method II. Wild type (unmodified) and 3'→5' exonuclease deficient forms of T4 DNA polymerase and the 3'-»5' exonuclease deficient form of E. coli DNA polymerase II can be used as DNA sequencing polymerases with 3' amino-2', 3'- dideoxyribonucleotides (Fig. 1) as chain terminating nucleotides. Method II reactions for the exonuclease deficient form of E. coli DNA polymerase II are shown in Fig. 2, panel A, lanes 5-7. Lane five shows the reaction with 3'amino-2',3'- dideoxyGTP; lane 6 shows the reaction with 3'amino-2',3'-dideoxyATP; lane 7 shows the reaction with 3'amino-2',3-dideoxyTTP. Method II reactions for the exonuclease deficient form of T4 DNA polymerase are shown in panel B, lanes 5-7. Lane 5, 6 and 7 show reactions with 3 'amino-2' 3 'dideoxyGTP, -ATP and -TTP, respectively. The data demonstrate that the exonuclease deficient forms of E. coli DNA polymerase II and bacteriophage T4 DNA polymerases can produce DNA sequence information using a combination of the following chain-terminating nucleotides: ddGTP or 3'amino-2', 3 '-dideoxyGTP; ddATP or 3'amino-2',3'- dideoxyATP; araUTP or 3'amino-2',3'dideoxy-TTP; and araCTP. In view of the good sequence patterns obtained with 3'amino-2'3'dideoxy-GTP, -ATP and -TTP, it is likely that 3'amino-2' ,3'-dideoxy-CTP will also be an effective chain-terminating nucleotide. No attempt was made to optimize conditions for Methods I or II in order to achieve equal band intensities or to increase the length of readable sequence for the reactions shown in Fig. 2. Nevertheless, the sequencing methods can provide sequence information for at least 300 bases. The exonuclease deficient form of T4 DNA polymerase is not required for sequencing reactions with the 3'amino-2',3'- dideoxyribonucleoside triphosphates. Sample Experimental conditions for Methods I and II (Figure 2). Labeling reaction. 5 μl exonuclease deficient DNA polymerase; 300-400 units/ml for T4 DNA polymerase or for E. coli DNA polymerase II. One unit T4 DNA polymerase catalyzes 10 nmol of dTMP incorporation into DNA in 30 min at 30°C. One unit of E. coli DNA polymerase II catalyzes the incorporation of 1 pmol of dTMP into DNA in 1 min at 37°C. Although the reaction is typically conducted at 37°C, the reaction may be conducted in a temperature range from about 35 °C to about 42 °C. 15 μl primer-M13 DNA complex, 15 nM 15 μl labeling reaction solution: 2 μM dGTP, dCTP, dTTP; 1 μM [α∞FldATP; 50 mM Tris-HCl (pH 8.5); 5 mM MgCl 2 or 6 mM MnCl 2 for E. coli DNA polymerase II; 5 mM MgCl 2 or 0.5 mM MnCl 2 for T4 DNA polymerase; 5 mM dithiothreitol; 50 μg/ml bovine serum albumin. The reaction mixtures were incubated 5 min at 37°C. The primer may also be labeled at the 5'-end, or by including a labeled nucleotide in the extension reaction and by other standard methods. Extension reaction. 4 μl labeling reaction mixture (from above) 4 μl termination solution: 50 μM dGTP, dATP, dCTP and dTTP; and one of the termination analogs listed below: Method I: ddGTP, 1.6 mM; ddATP, 0.7 mM; araCTP, 0.5 mM; araUTP, 0.5mM. Method II: 3 '-amino-2', 3 '-dideoxyGTP, 0.5 mM; 3'-amino-2',3'- dideoxyATP, 0.5 mM; 3'-amino-2',3'-dideoxyTTP, 0.5mM Reactions were incubated at 5 min at 37 °C. Reactions were stopped by adding formamide/EDTA. DNA sequencing Method III (Figure 3). Exonuclease deficient T4 DNA polymerase can produce DNA sequence information in reactions where one dNTP is at a low concentration (for example, 0.1 μM to 1 μM) and the other three dNTPs are at high concentrations (100 μM) (Fig. 3). DNA sequencing patterns are produced as with sequencing reactions with nucleotide analogs except that sequencing products produced by this method terminate one position before the dNTP at low concentrations is required. Sample Experimental conditions: 25 mM Hepes (pH 7.5) 60 mM NaOAc 1 mM dithiothreitol 100 μM dGTP, dCTP and dTTP 0.1 μM dATP (1 μM dATP for longer DNA products) 0.2 mg/ml bovine serum albumin 7.5 nM 5 '[ 32 P] labeled primer-template (expressed as the concentration of 3 '-primer termini) 30 nM exonuclease deficient T4 DNA polymerase 6 mM Mg(OAc) 2 The reaction shown in Fig. 3 contained 0.1 μM dATP and was incubated for 1 min at 30 °C. Conditions have not been optimized to obtain high amounts of sequence information; however, reactions in which the low concentration dNTP is at 1 μM yield sequence information greater than 100 bases. Isolation of Novel T4 DNA Polvmerases with Properties Advantageous for DNA Sequencing. The first step in this aspect of the invention is to identify T4 strains with variant (mutant) DNA polymerases defective in some aspect of DNA replication. T4 strains with mutant DNA polymerase that have the amino acid substitutions listed below were chosen, but the genetic selection strategy is not limited to these mutants as any mutant DNA polymerase with defective DNA replication ability can be used. Variant (mutant) T4 DNA polymerases that are partially defective in some aspect of DNA replication cannot replicate DNA in the E. coli optAl host. T4 strains with mutant DNA polymerases with amino acid substitutions W213S, I417V, A737V or A777V cannot replicate DNA in the E. coli optAl host. To achieve these variants the following mutations were employed: for W213S the G nucleotide at position 637 is replaced with a C nucleotide; for 1417V the A nucleotide at position 1249 is replaced with a G nucleotide; for A737V the C nucleotide at position 2209 is replaced with a T nucleotide; and for A777V the C nucleotide at position 2329 is replaced with a T nucleotide. As is known other nucleotide replacements can cause the same amino acid changes. The second step is to select T4 strains that can replicate DNA in the E. coli optAl host even though the DNA polymerase still retains the amino acid substitution that alone reduces DNA replication ability and prevents replication of DNA in E. coli optAl host. T4 strains that have acquired a second DNA polymerase mutation (or multiple mutations), either by spontaneous mutation or by mutagenesis treatment, that encodes a new amino acid substitution that can correct or compensate the DNA replication defect produced by the first amino acid substitution, will be able to replicate DNA in the E. coli optAl host and produce phage progeny. DNA polymerases thus identified have at least two amino acid substitutions: the starting amino acid substitution and one or more new amino acid substitutions that restore DNA replication activity. This genetic selection strategy is of high sensitivity. A phage with a mutant DNA polymerase containing the starting amino acid substitution and the amino acid substitution(s) that restores DNA replication activity can be selected from a population of 10 8 to IO 9 phage. The third step is to identify the DNA replication restoring mutation(s). This step utilizes standard sequencing procedures to find the new mutation(s) in the T4 DNA polymerase gene. Once the new mutation(s) has been identified, the mutation can be introduced into phage or into T4 DNA polymerase expression vectors using standard procedures. Unlike the starting, DNA replication defective DNA polymerase, the DNA polymerases with the correcting or compensating amino acid substitutions have superior DNA replication activity. A sample of the amino acid substitutions discovered using the genetic selection strategy described above include but are not limited to: I50L, G82D, G255S and Ε743K. To achieve these variants the following mutations were employed: for I50L the A nucleotide at position 148 is replaced with a C nucleotide; for G82D the G nucleotide at position 244 is replaced with an A nucleotide; for G255S the G nucleotide at position 763 is replaced with an A nucleotide; and for E743K the G nucleotide at position 2227 is replaced with an A nucleotide. As is known other nucleotide replacements can effect the same amino acid changes. Variant (mutant, modified) T4 DNA polymerases with amino acid substitutions that confer enhanced DNA replication activity have new properties advantageous for DNA sequencing. One frequent DNA sequencing problem is that DNA polymerases used in sequencing reactions pause or disassociate at some template sites. As a consequence of this premature stop in chain elongation, sequencing products are produced that are not terminated by a chain-terminating nucleotide. Another problem is that DNA polymerase incorporation of nucleotides and chain-terminating nucleotides is affected by the template sequence which may lead to an unequal distribution of sequencing products. Novel DNA polymerases with enhanced DNA replication activity may surmount these problems. The G82D- T4 DNA polymerase (also known as T4 mel 62 DNA polymerase) has been tested in primer extension assays and this novel DNA polymerase has been found to extend primers that are problematic for the wild type T4 DNA polymerase. An example of G82D-T4 DNA polymerase synthesis is given in Figure 4. Figure 4 depicts the use of three T4 polymerases to copy a DNA template lesion (an abasic lesion - a base is missing on the template strand, indicated by X). The wild-type T4 polymerase has difficulty incorporating a nucleotide opposite X, as shown by the very light bands. A 3 '-exonuclease deficient T4 polymerase mutant, EXO 17, is able to incorporate nucleotides opposite X (note the intense band at X) and continue synthesis beyond the lesion. The T4 mel 62 polymerase is a mutant enzyme (it conveys a imitator phenotype in vivo) that has apparent normal (wild-type) levels of 3 '-exonuclease and polymerase activities. It nevertheless is also able to incorporate nucleotides opposite X and to continue synthesis beyond X. What is most interesting is that the absence of "pausing" bands beyond X suggests that the mel 62 DNA polymerase remains bound to the primer template DNA more tightly than either EXO 17 or the wild-type polymerases. Thus, it is possible that this enzyme may be able to overcome template and substrate obstacles to synthesize long stretches of DNA. It is contemplated that one or more amino acid substitutions that confer superior DNA replication activity will be combined with one or more amino acid substitutions that significantly reduce 3'-»5' exonuclease activity to create a multiply modified novel T4 DNA polymerase with several properties that are advantageous for DNA sequencing polymerases. It is known that polymerases, such as bacteriophage T7 DNA polymerase, may be used in conjunction with their accessory proteins thereby increasing the processivity of the polymerase by decreasing the rate of disassociation of the polymerase from the DNA strand to be sequenced. In the case of the T4 polymerase, its accessory proteins, include but are not limited to, the following T4 gene products: gene product 32, 41, 45 and the 44/62 complex. In the case of E. coli DNA polymerase II, the accessory proteins are the following: β protein; the y protein complex wherein the y complex is composed of y, δ, δ' , χ, ; and SSB (single stranded binding protein) (note that β protein and y complex are E. coli pol III accessory proteins). Use of these accessory proteins enhances the efficiency of the polymerases in sequencing DNA. While there have been shown and described the fundamental novel features of the invention, it will be understood that various omissions, substitutions and changes in the form and details illustrated may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims. SEQUENCE LISTING (1) GENERAL INFORMATION: (i) APPLICANT: Goodman, Myron F. Reha-Krantz, Linda J. (ii) TITLE OF INVENTION: NEW DNA SEQUENCING ENZYMES (iii) NUMBER OF SEQUENCES: 6 (iv) CORRESPONDENCE ADDRESS: (A) ADDRESSEE: Robbins, Berliner & Carspm (B) STREET: 201 North Figueroa Street, Fifth Floor (C) CITY: Los Angeles (D) STATE: California (E) COUNTRY: U.S.A. (F) ZIP: 90012-2628 (v) COMPUTER READABLE FORM: (A) MEDIUM TYPE: Floppy disk (B) COMPUTER: IBM PC compatible (C) OPERATING SYSTEM: PC-DOS/MS-DOS (D) SOFTWARE: Patentln Release #1.0, Version #1.25 (vi) CURRENT APPLICATION DATA: (A) APPLICATION NUMBER: (B) FILING DATE: (C) CLASSIFICATION: (viii) ATTORNEY/AGENT INFORMATION: (A) NAME: Spitals, John P. (B) REGISTRATION NUMBER: 29,215 (C) REFERENCE/DOCKET NUMBER: 1920-305 (ix) TELECOMMUNICATION INFORMATION: (A) TELEPHONE: (213) 977-1001 (B) TELEFAX: (213) 977-1003 (2) INFORMATION FOR SEQ ID NO:1: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 2760 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: DNA (genomic) (ix) FEATURE: (A) NAME/KEY: CDS (B) LOCATION: 1..2760 (xi) SEQUENCE DESCRIPTION: SEQ ID NO:1: CGT CAT CTT CAT TTT TTT TTT TTT TTT TTT TTT TTT TTT TTT TTT TTT 48 Arg His Leu His Phe Phe Phe Phe Phe Phe Phe Phe Phe Phe Phe Phe 1 5 10 15 TTT TTT TTT TTT ATT ATT ATG AAA GAA TTT TAT ATC TCT ATC GAA ACA 96 Phe Phe Phe Phe He He Met Lys Glu Phe Tyr He Ser He Glu Thr 20 25 30 GTC GGA AAT AAT ATT ATT GAA CGT TAT ATT GAT GAA AAC GGA AAG GAA 144 Val Gly Asn Asn He He Glu Arg Tyr He Asp Glu Asn Gly Lys Glu 35 40 45 CGT ACT CGT GAA GTA GAA TAT CTT CCG ACT ATG TTT AGG CAT TGT AAG 192 Arg Thr Arg Glu Val Glu Tyr Leu Pro Thr Met Phe Arg His Cys Lys 50 55 60 GAA GAG TCA AAA TAC AAA GAC ATC TAT GGT AAA AAC TGT GCT CCT CAA 240 Glu Glu Ser Lys Tyr Lys Asp He Tyr Gly Lys Asn Cys Ala Pro Gin 65 70 75 80 AAA TTT CCA TCA ATG AAA GAT GCT CGA GAT TGG ATG AAG CGA ATG GAA 288 Lys Phe Pro Ser Met Lys Asp Ala Arg Asp Trp Met Lys Arg Met Glu 85 90 95 GAC ATC GGT CTC GAA GCT CTC GGT ATG AAC GAT TTT AAA CTC GCT TAT 336 Asp He Gly Leu Glu Ala Leu Gly Met Asn Asp Phe Lys Leu Ala Tyr 100 105 110 ATC AGT GAT ACG TAT GGT TCA GAA ATT GTT TAT GAC CGA AAA TTT GTT 384 He Ser Asp Thr Tyr Gly Ser Glu He Val Tyr Asp Arg Lys Phe Val 115 120 125 CGT GTA GCT AAC TGT GAC ATT GAG GTT ACT GGT GAT AAA TTT CCT GAC 432 Arg Val Ala Asn Cys Asp He Glu Val Thr Gly Asp Lys Phe Pro Asp 130 135 140 CCA ATG AAA GCA GAA TAT GAA ATT GAT GCT ATC ACT CAT TAT GAT TCA 480 Pro Met Lys Ala Glu Tyr Glu He Asp Ala He Thr His Tyr Asp Ser 145 150 155 160 ATT GAC GAC CGT TTT TAT GTT TTC GAC CTT TTG AAT TCA ATG TAC GGT 528 He Asp Asp Arg Phe Tyr Val Phe Asp Leu Leu Asn Ser Met Tyr Gly 165 170 175 TCA GTA TCA AAA TGG GAT GCA AAG TTA GCT GCT AAG CTT GAC TGT GAA 576 Ser Val Ser Lys Trp Asp Ala Lys Leu Ala Ala Lys Leu Asp Cys Glu 180 185 190 GGT GGT GAT GAA GTT CCT CAA GAA ATT CTT GAC CGA GTA ATT TAT ATG 624 Gly Gly Asp Glu Val Pro Gin Glu He Leu Asp Arg Val He Tyr Met 195 200 205 CCA TTT GAT AAT GAG CGT GAT ATG CTC ATG GAA TAT ATT AAT CTC TGG 672 Pro Phe Asp Asn Glu Arg Asp Met Leu Met Glu Tyr He Asn Leu Trp 210 215 220 GAA CAG AAA CGA CCT GCT ATT TTT ACT GGT TGG AAT ATT GAG GGG TTT 720 Glu Gin Lys Arg Pro Ala He Phe Thr Gly Trp Asn He Glu Gly Phe 225 230 235 240 GAC GTT CCG TAT ATC ATG AAT CGC GTT AAA ATG ATT CTG GGT GAA CGC 768 Asp Vat Pro Tyr He Met Asn Arg Val Lys Met He Leu Gly Glu Arg 245 250 255 AGT ATG AAA CGT TTC TCT CCA ATC GGT CGG GTA AAA TCT AAA CTA ATT 816 Ser Met Lys Arg Phe Ser Pro He Gly Arg Val Lys Ser Lys Leu He 260 265 270 CAA AAT ATG TAC GGT AGC AAA GAA ATT TAT TCT ATT GAT GGC GTA TCT 864 Gin Asn Met Tyr Gly Ser Lys Glu He Tyr Ser He Asp Gly Val Ser 275 280 285 ATT CTT GAT TAT TTA GAT TTG TAC AAG AAA TTC GCT TTT ACT AAT TTG 912 He Leu Asp Tyr Leu Asp Leu Tyr Lys Lys Phe Ala Phe Thr Asn Leu 290 295 300 CCG TCA TTC TCT TTG GAA TCA GTT GCT CAA CAT GAA ACC AAA AAA GGT 960 Pro Ser Phe Ser Leu Glu Ser Val Ala Gin His Glu Thr Lys Lys Gly 305 310 315 320 AAA TTA CCA TAC GAC GGT CCT ATT AAT AAA CTT CGT GAG ACT AAT CAT 1008 Lys Leu Pro Tyr Asp Gly Pro He Asn Lys Leu Arg Glu Thr Asn His 325 330 335 CAA CGA TAC ATT AGT TAT AAC ATC ATT GAC GTA GAA TCA GTT CAA GCA 1056 Gin Arg Tyr He Ser Tyr Asn He He Asp Val Glu Ser Val Gin Ala 340 345 350 ATT GAT AAA ATT CGT GGG TTT ATC GAT CTA GTT TTA AGT ATG TCT TAT 1104 He Asp Lys He Arg Gly Phe He Asp Leu Val Leu Ser Met Ser Tyr 355 360 365 TAT GCT AAA ATG CCT TTT TCT GGT GTA ATG AGT CCT ATT AAA ACT TGG 1152 Tyr Ala Lys Met Pro Phe Ser Gly Val Met Ser Pro He Lys Thr Trp 370 375 380 GAT GCT ATT ATT TTT AAC TCA TTG AAA GGT GAA CAC AAG GTT ATT CCT 1200 Asp Ala He He Phe Asn Ser Leu Lys Gly Glu His Lys Val He Pro 385 390 395 400 CAA CAA GGT TCG CAC GTT AAA CAG AGT TTT CCG GGT GCA TTT GTA TTT 1248 Gin Gin Gly Ser His Val Lys Gin Ser Phe Pro Gly Ala Phe Val Phe 405 410 415 GAA CCT AAA CCA ATT GCT CGT CGA TAC ATT ATG AGT TTT GAC TTG ACG 1296 Glu Pro Lys Pro He Ala Arg Arg Tyr He Met Ser Phe Asp Leu Thr 420 425 430 TCT CTG TAT CCG AGC ATT ATT CGC CAG GTT AAC ATT AGT CCT GAA ACT 1344 Ser Leu Tyr Pro Ser He He Arg Gin Vat Asn He Ser Pro Glu Thr 435 440 445 ATT CGT GGT CAG TTT AAA GTT CAT CCA ATT CAT GAA TAT ATC GCA GGA 1392 He Arg Gly Gin Phe Lys Val His Pro He His Glu Tyr He Ala Gly 450 455 460 ACA GCT CCT AAA CCA AGT GAT GAA TAT TCT TGT TCT CCG AAT GGA TGG 1440 Thr Ala Pro Lys Pro Ser Asp Glu Tyr Ser Cys Ser Pro Asn Gly Trp 465 470 475 480 ATG TAT GAT AAG CAT CAA GAA GGT ATC ATT CCA AAG GAA ATC GCT AAA 1488 Met Tyr Asp Lys His Gin Glu Gly He He Pro Lys Glu He Ala Lys 485 490 495 GTA TTT TTC CAG CGT AAA GAT TGG AAA AAG AAA ATG TTC GCT GAA GAA 1536 Val Phe Phe Gin Arg Lys Asp Trp Lys Lys Lys Met Phe Ala Glu Glu 500 505 510 ATG AAT GCC GAA GCT ATT AAA AAG ATT ATT ATG AAA GGC GCA GGG TCT 1584 Met Asn Ala Glu Ala He Lys Lys He He Met Lys Gly Ala Gly Ser 515 520 525 TGT TCA ACT AAA CCA GAA GTT GAA CGA TAT GTT AAG TTC ACT GAT GAT 1632 Cys Ser Thr Lys Pro Glu Val Glu Arg Tyr Val Lys Phe Thr Asp Asp 530 535 540 TTC TTA AAT GAA CTA TCG AAT TAT ACT GAA TCT GTT CTT AAT AGT CTG 1680 Phe Leu Asn Glu Leu Ser Asn Tyr Thr Glu Ser Val Leu Asn Ser Leu 545 550 555 560 ATT GAA GAA TGT GAA AAA GCA GCT ACA CTT GCT AAT ACA AAT CAG CTG 1728 He Glu Glu Cys Glu Lys Ala Ala Thr Leu Ala Asn Thr Asn Gin Leu 565 570 575 AAC CGT AAA ATT CTT ATT AAC AGT CTT TAT GGT GCT CTT GGT AAT ATT 1776 Asn Arg Lys He Leu He Asn Ser Leu Tyr Gly Ala Leu Gly Asn He 580 585 590 CAT TTC CGT TAC TAT GAT TTA CGA AAT GCT ACT GCT ATC ACA ATT TTT 1824 His Phe Arg Tyr Tyr Asp Leu Arg Asn Ala Thr Ala He Thr He Phe 595 600 605 GGT CAA GTT GGT ATT CAG TGG ATT GCT CGT AAA ATT AAT GAA TAT CTG 1872 Gly Gin Val Gly He Gin Trp He Ala Arg Lys He Asn Glu Tyr Leu 610 615 620 AAT AAA GTA TGC GGA ACT AAT GAT GAA GAT TTC ATC GCA GCA GGT GAT 1920 Asn Lys Val Cys Gly Thr Asn Asp Glu Asp Phe He Ala Ala Gly Asp 625 630 635 640 ACT GAT TCG GTA TAT GTT TGT GTA GAT AAA GTT ATT GAA AAA GTT GGT 1968 Thr Asp Ser Val Tyr Val Cys Val Asp Lys Vat He Glu Lys Val Gly 645 650 655 CTT GAC CGA TTC AAA GAG CAG AAC GAT TTG GTT GAA TTC ATG AAT CAG 2016 Leu Asp Arg Phe Lys Glu Gin Asn Asp Leu Val Glu Phe Met Asn Gin 660 665 670 TTT GGT AAG AAA AAG ATG GAA CCT ATG ATT GAT GTT GCA TAT CGT GAG 2064 Phe Gly Lys Lys Lys Met Glu Pro Met He Asp Val Ala Tyr Arg Glu 675 680 685 TTA TGT GAT TAT ATG AAT AAC CGC GAG CAT CTG ATG CAT ATG GAC CGT 2112 Leu Cys Asp Tyr Met Asn Asn Arg Glu His Leu Met His Met Asp Arg 690 695 700 GAA GCT ATT TCT TGC CCT CCG CTT GGT TCA AAG GGT GTT GGT GGA TTT 2160 Glu Ala He Ser Cys Pro Pro Leu Gly Ser Lys Gly Val Gly Gly Phe 705 710 715 720 TGG AAA GCG AAA AAA CGT TAT GCT CTG AAC GTT TAT GAT ATG GAA GAT 2208 Trp Lys Ala Lys Lys Arg Tyr Ala Leu Asn Val Tyr Asp Met Glu Asp 725 730 735 AAG CGA TTT GCT GAA CCG CAT CTA AAA ATC ATG GGT ATG GAA ACT CAG 2256 Lys Arg Phe Ala Glu Pro His Leu Lys He Met Gly Met Glu Thr Gin 740 745 750 CAG AGT TCA ACA CCA AAA GCA GTG CAA GAA GCA CTC GAA GAA AGT ATT 2304 Gin Ser Ser Thr Pro Lys Ala Val Gin Glu Ala Leu Glu Glu Ser He 755 760 765 CGT CGT ATT CTT CAG GAA GGC GAA GAG TCT GTC CAA GAA TAT TAC AAG 2352 Arg Arg He Leu Gin Glu Gly Glu Glu Ser Val Gin Glu Tyr Tyr Lys 770 775 780 AAC TTC GAG AAA GAA TAT CGT CAA CTT GAC TAT AAA GTT ATT GCT GAA 2400 Asn Phe Glu Lys Glu Tyr Arg Gin Leu Asp Tyr Lys Val He Ala Glu 785 790 795 800 GTA AAA ACT GCG AAC GAT ATA GCG AAA TAT GAT GAT AAA GGT TGG CCA 2448 Val Lys Thr Ala Asn Asp He Ala Lys Tyr Asp Asp Lys Gly Trp Pro 805 810 815 GGA TTT AAA TGT CCG TTC CAT ATT CGT GGT GTG CTA ACT TAT CGT CGA 2496 Gly Phe Lys Cys Pro Phe His He Arg Gly Val Leu Thr Tyr Arg Arg 820 825 830 GCT GTT AGT GGT CTG GGT GTA GCT CCA ATT TTG GAT GGA AAT AAA GTA 2544 Ala Val Ser Gly Leu Gly Val Ala Pro He Leu Asp Gly Asn Lys Val 835 840 845 ATG GTT CTT CCA TTA CGT GAA GGA AAT CCG TTT GGT GAT AAG TGC ATT 2592 Met Val Leu Pro Leu Arg Glu Gly Asn Pro Phe Gly Asp Lys Cys He 850 855 860 GCT TGG CCA TCG GGT ACA GAA CTT CCA AAA GAA ATT CGT TCT GAT GTA 2640 Ala Trp Pro Ser Gly Thr Glu Leu Pro Lys Glu He Arg Ser Asp Val 865 870 875 880 CTA TCT TGG ATT GAC TAC TCA ACT TTG TTC CAA AAA TCG TTT GTT AAA 2688 Leu Ser Trp He Asp Tyr Ser Thr Leu Phe Gin Lys Ser Phe Val Lys 885 890 895 CCG CTT GCG GGT ATG TGT GAA TCG GCA GGT ATG GAC TAT GAG GAA AAA 2736 Pro Leu Ala Gly Met Cys Glu Ser Ala Gly Met Asp Tyr Glu Glu Lys 900 905 910 GCT TCG TTA GAC TTC CTG TTT GGC 2760 Ala Ser Leu Asp Phe Leu Phe Gly 915 920 (2) INFORMATION FOR SEQ ID NO:2: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 920 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: protein (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2: Arg His Leu His Phe Phe Phe Phe Phe Phe Phe Phe Phe Phe Phe Phe 1 5 10 15 Phe Phe Phe Phe He He Met Lys Glu Phe Tyr He Ser He Glu Thr 20 25 30 Val Gly Asn Asn He He Glu Arg Tyr He Asp Glu Asn Gly Lys Glu 35 40 45 Arg Thr Arg Glu Val Glu Tyr Leu Pro Thr Met Phe Arg His Cys Lys 50 55 60 Glu Glu Ser Lys Tyr Lys Asp He Tyr Gly Lys Asn Cys Ala Pro Gin 65 70 75 80 Lys Phe Pro Ser Met Lys Asp Ala Arg Asp Trp Met Lys Arg Met Glu 85 90 95 Asp He Gly Leu Glu Ala Leu Gly Met Asn Asp Phe Lys Leu Ala Tyr 100 105 110 He Ser Asp Thr Tyr Gly Ser Glu He Val Tyr Asp Arg Lys Phe Val 115 120 125 Arg Val Ala Asn Cys Asp He Glu Val Thr Gly Asp Lys Phe Pro Asp 130 135 140 Pro Met Lys Ala Glu Tyr Glu He Asp Ala He Thr His Tyr Asp Ser 145 150 155 160 He Asp Asp Arg Phe Tyr Val Phe Asp Leu Leu Asn Ser Met Tyr Gly 165 170 175 Ser Val Ser Lys Trp Asp Ala Lys Leu Ala Ala Lys Leu Asp Cys Glu 180 185 190 Gly Gly Asp Glu Val Pro Gin Glu He Leu Asp Arg Val He Tyr Met 195 200 205 Pro Phe Asp Asn Glu Arg Asp Met Leu Met Glu Tyr He Asn Leu Trp 210 215 220 Glu Gin Lys Arg Pro Ala He Phe Thr Gly Trp Asn He Glu Gly Phe 225 230 235 240 Asp Val Pro Tyr He Met Asn Arg Val Lys Met He Leu Gly Glu Arg 245 250 255 Ser Met Lys Arg Phe Ser Pro He Gly Arg Val Lys Ser Lys Leu He 260 265 270 Gin Asn Met Tyr Gly Ser Lys Glu He Tyr Ser He Asp Gly Val Ser 275 280 285 He Leu Asp Tyr Leu Asp Leu Tyr Lys Lys Phe Ala Phe Thr Asn Leu 290 295 300 Pro Ser Phe Ser Leu Glu Ser Val Ala Gin His Glu Thr Lys Lys Gly 305 310 315 320 Lys Leu Pro Tyr Asp Gly Pro He Asn Lys Leu Arg Gtu Thr Asn His 325 330 335 Gin Arg Tyr He Ser Tyr Asn He He Asp Val Glu Ser Val Gin Ala 340 345 350 He Asp Lys He Arg Gly Phe He Asp Leu Val Leu Ser Met Ser Tyr 355 360 365 Tyr Ala Lys Met Pro Phe Ser Gly Val Met Ser Pro He Lys Thr Trp 370 375 380 Asp Ala He He Phe Asn Ser Leu Lys Gly Glu His Lys Val He Pro 385 390 395 400 Gin Gin Gly Ser His Val Lys Gin Ser Phe Pro Gly Ala Phe Val Phe 405 410 415 Glu Pro Lys Pro He Ala Arg Arg Tyr He Met Ser Phe Asp Leu Thr 420 425 430 Ser Leu Tyr Pro Ser He He Arg Gin Val Asn He Ser Pro Glu Thr 435 440 445 He Arg Gly Gin Phe Lys Val His Pro He His Gtu Tyr He Ala Gly 450 455 460 Thr Ala Pro Lys Pro Ser Asp Glu Tyr Ser Cys Ser Pro Asn Gly Trp 465 470 475 480 Met Tyr Asp Lys His Gin Glu Gly He He Pro Lys Glu He Ala Lys 485 490 495 Val Phe Phe Gin Arg Lys Asp Trp Lys Lys Lys Met Phe Ala Glu Glu 500 505 510 Met Asn Ala Glu Ala He Lys Lys He He Met Lys Gly Ala Gly Ser 515 520 525 Cys Ser Thr Lys Pro Glu Vat Glu Arg Tyr Val Lys Phe Thr Asp Asp 530 535 540 Phe Leu Asn Glu Leu Ser Asn Tyr Thr Glu Ser Val Leu Asn Ser Leu 545 550 555 560 He Glu Glu Cys Glu Lys Ala Ala Thr Leu Ala Asn Thr Asn Gin Leu 565 570 575 Asn Arg Lys He Leu He Asn Ser Leu Tyr Gly Ala Leu Gly Asn He 580 585 590 His Pho Arg Tyr Tyr Asp Leu Arg Asn Ala Thr Ala He Thr He Phe 595 600 605 Gly Gin Val Gly He Gin Trp He Ala Arg Lys He Asn Glu Tyr Leu 610 615 620 Asn Lys Vat Cys Gly Thr Asn Asp Glu Asp Phe He Ala Ala Gly Asp 625 630 635 640 Thr Asp Ser Val Tyr Val Cys Val Asp Lys Val He Glu Lys Val Gly 645 650 655 Leu Asp Arg Phe Lys Glu Gin Asn Asp Leu Val Glu Phe Met Asn Gin 660 665 670 Phe Gly Lys Lys Lys Met Glu Pro Met He Asp Val Ala Tyr Arg Glu 675 680 685 Leu Cys Asp Tyr Met Asn Asn Arg Glu His Leu Met His Met Asp Arg 690 695 700 Glu Ala He Ser Cys Pro Pro Leu Gly Ser Lys Gly Val Gly Gly Phe 705 710 715 720 Trp Lys Ala Lys Lys Arg Tyr Ala Leu Asn Val Tyr Asp Met Glu Asp 725 730 735 Lys Arg Phe Ala Glu Pro His Leu Lys He Met Gly Met Glu Thr Gin 740 745 750 Gin Ser Ser Thr Pro Lys Ala Val Gin Glu Ala Leu Glu Glu Ser He 755 760 765 Arg Arg He Leu Gin Glu Gly Glu Glu Ser Val Gin Glu Tyr Tyr Lys 770 775 780 Asn Phe Glu Lys Glu Tyr Arg Gin Leu Asp Tyr Lys Val He Ala Glu 785 790 795 BOO Val Lys Thr Ala Asn Asp He Ala Lys Tyr Asp Asp Lys Gly Trp Pro 805 810 815 Gly Phe Lys Cys Pro Phe His He Arg Gly Val Leu Thr Tyr Arg Arg 820 825 830 Ala Vat Ser Gly Leu Gly Val Ala Pro He Leu Asp Gly Asn Lys Val 835 840 845 Met Val Leu Pro Leu Arg Glu Gly Asn Pro Phe Gly Asp Lys Cys He 850 855 860 Ala Trp Pro Ser Gly Thr Glu Leu Pro Lys Glu He Arg Ser Asp Val 865 870 875 880 Leu Ser Trp He Asp Tyr Ser Thr Leu Phe Gin Lys Ser Phe Val Lys 885 890 895 Pro Leu Ala Gly Met Cys Glu Ser Ala Gly Met Asp Tyr Glu Glu Lys 900 905 910 Ala Ser Leu Asp Phe Leu Phe Gly 915 920 (2) INFORMATION FOR SEQ ID NO:3: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 2760 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: DNA (genomic) (ix) FEATURE: (A) NAME/KEY: CDS (B) LOCATION: 1..2760 (xi) SEQUENCE DESCRIPTION: SEQ ID N0:3: CGT CAT CTT CAT TTT TTT TTT TTT TTT TTT TTT TTT TTT TTT TTT TTT 48 Arg His Leu His Phe Phe Phe Phe Phe Phe Phe Phe Phe Phe Phe Phe 1 5 10 15 TTT TTT TTT TTT ATT ATT ATG AAA GAA TTT TAT ATC TCT ATT GAA ACA 96 Phe Phe Phe Phe He He Met Lys Glu Phe Tyr He Ser He Glu Thr 20 25 30 GTC GGA AAT AAC ATT GTT GAA CGT TAT ATT GAT GAA AAT GGA AAG GAA 144 Val Gly Asn Asn He Val Glu Arg Tyr He Asp Glu Asn Gly Lys Glu 35 40 45 CGT ACC CGT GAA GTA GAA TAT CTT CCA ACT ATG TTT AGG CAT TGT AAG 192 Arg Thr Arg Glu Val Glu Tyr Leu Pro Thr Met Phe Arg His Cys Lys 50 55 60 GAA GAG TCA AAA TAC AAA GAC ATC TAT GGT AAA AAC TGC GCT CCT CAA 240 Glu Glu Ser Lys Tyr Lys Asp He Tyr Gly Lys Asn Cys Ala Pro Gin 65 70 75 80 AAA TTT CCA TCA ATG AAA GAT GCT CGA GAT TGG ATG AAG CGA ATG GAA 288 Lys Phe Pro Ser Met Lys Asp Ala Arg Asp Trp Met Lys Arg Met Glu 85 90 95 GAC ATC GGT CTC GAA GCT CTC GGT ATG AAC GAT TTT AAA CTC GCT TAT 336 Asp He Gly Leu Glu Ala Leu Gly Met Asn Asp Phe Lys Leu Ala Tyr 100 105 110 ATA AGT GAT ACA TAT GGT TCA GAA ATT GTT TAT GAC CGA AAA TTT GTT 384 He Ser Asp Thr Tyr Gly Ser Glu He Val Tyr Asp Arg Lys Phe Val 115 120 125 CGT GTA GCT AAC TGT GAC ATT GAG GTT ACT GGT GAT AAA TTT CCT GAC 432 Arg Val Ala Asn Cys Asp He Gtu Val Thr Gly Asp Lys Phe Pro Asp 130 135 140 CCA ATG AAA GCA GAA TAT GAA ATT GAT GCT ATC ACT CAT TAC GAT TCA 480 Pro Met Lys Ala Glu Tyr Glu He Asp Ala He Thr His Tyr Asp Ser 145 150 155 160 ATT GAC GAT CGT TTT TAT GTT TTC GAC CTT TTG AAT TCA ATG TAC GGT 528 He Asp Asp Arg Phe Tyr Val Phe Asp Leu Leu Asn Ser Met Tyr Gly 165 170 175 TCA GTA TCA AAA TGG GAT GCA AAG TTA GCT GCT AAG CTT GAC TGT GAA 576 Ser Val Ser Lys Trp Asp Ala Lys Leu Ala Ala Lys Leu Asp Cys Glu 180 185 190 GGT GGT GAT GAA GTT CCT CAA GAA ATT CTT GAC CGA GTA ATT TAT ATG 624 Gty Gly Asp Glu Val Pro Gin Glu He Leu Asp Arg Val He Tyr Met 195 200 205 CCA TTC GAT AAT GAG CGT GAT ATG CTC ATG GAA TAT ATC AAT CTT TGG 672 Pro Phe Asp Asn Glu Arg Asp Met Leu Met Glu Tyr He Asn Leu Trp 210 215 220 GAA CAG AAA CGA CCT GCT ATT TTT ACT GGT TGG AAT ATT GAG GGG TTT 720 Glu Gin Lys Arg Pro Ala He Phe Thr Gly Trp Asn He Glu Gly Phe 225 230 235 240 GAC GTT CCG TAT ATC ATG AAT CGT GTT AAA ATG ATT CTG GGT GAA CGT 768 Asp Val Pro Tyr He Met Asn Arg Val Lys Met He Leu Gly Glu Arg 245 250 255 AGT ATG AAA CGT TTC TCT CCA ATC GGT CGG GTA AAA TCT AAA CTA ATT 816 Ser Met Lys Arg Phe Ser Pro He Gly Arg Val Lys Ser Lys Leu He 260 265 270 CAA AAT ATG TAC GGT AGC AAA GAA ATT TAT TCT ATT GAT GGC GTA TCT 864 Gin Asn Met Tyr Gly Ser Lys Glu He Tyr Ser He Asp Gly Val Ser 275 280 285 ATT CTT GAT TAT TTA GAT TTG TAC AAG AAA TTC GCT TTT ACT AAT TTG 912 He Leu Asp Tyr Leu Asp Leu Tyr Lys Lys Phe Ala Phe Thr Asn Leu 290 295 300 CCG TCA TTC TCT TTG GAA TCA GTT GCT CAA CAT GAA ACC AAA AAA GGT 960 Pro Ser Phe Ser Leu Glu Ser Val Ala Gin His Glu Thr Lys Lys Gly 305 310 315 320 AAA TTA CCA TAC GAC GGT CCT ATT AAT AAA CTT CGT GAG ACT AAT CAT 1008 Lys Leu Pro Tyr Asp Gly Pro He Asn Lys Leu Arg Glu Thr Asn His 325 330 335 CAA CGA TAC ATT AGT TAT AAC ATC ATT GAC GTA GAA TCA GTT CAA GCA 1056 Gin Arg Tyr He Ser Tyr Asn He He Asp Val Glu Ser Val Gin Ala 340 345 350 ATC GAT AAA ATT CGT GGG TTT ATC GAT CTA GTT TTA AGT ATG TCT TAT 1104 He Asp Lys He Arg Gty Phe He Asp Leu Val Leu Ser Met Ser Tyr 355 360 365 TAC GCT AAA ATG CCT TTT TCT GGT GTA ATG AGT CCT ATT AAA ACT TGG 1152 Tyr Ala Lys Met Pro Phe Ser Gty Vat Met Ser Pro He Lys Thr Trp 370 375 380 GAT GCT ATT ATT TTT AAC TCA TTG AAA GGT GAA CAT AAG GTT ATT CCT 1200 Asp Ala He He Phe Asn Ser Leu Lys Gly Glu His Lys Val He Pro 385 390 395 400 CAA CAA GGT TCG CAC GTT AAA CAG AGT TTT CCG GGT GCA TTT GTG TTT 1248 Gin Gin Gly Ser His Val Lys Gin Ser Phe Pro Gly Ala Phe Val Phe 405 410 415 GAA CCT AAA CCA ATT GCA CGT CGA TAC ATT ATG AGT TTT GAC TTG ACG 1296 Glu Pro Lys Pro He Ala Arg Arg Tyr He Met Ser Phe Asp Leu Thr 420 425 430 TCT CTG TAT CCG AGC ATT ATT CGC CAG GTT AAC ATT AGT CCT GAA ACT 1344 Ser Leu Tyr Pro Ser He He Arg Gin Val Asn He Ser Pro Glu Thr 435 440 445 ATT CGT GGT CAG TTT AAA GTT CAT CCA ATT CAT GAA TAT ATC GCA GGA 1392 He Arg Gly Gin Phe Lys Val His Pro He His Glu Tyr He Ala Gly 450 455 460 ACA GCT CCT AAA CCG AGT GAT GAA TAT TCT TGT TCT CCG AAT GGA TGG 1440 Thr Ala Pro Lys Pro Ser Asp Glu Tyr Ser Cys Ser Pro Asn Gly Trp 465 470 475 480 ATG TAT GAT AAA CAT CAA GAA GGT ATC ATT CCA AAG GAA ATC GCT AAA 1488 Met Tyr Asp Lys His Gin Glu Gly He He Pro Lys Glu He Ala Lys 485 490 495 GTA TTT TTC CAG CGT AAA GAC TGG AAA AAG AAA ATG TTC GCT GAA GAA 1536 Val Phe Phe Gin Arg Lys Asp Trp Lys Lys Lys Met Phe Ala Glu Glu 500 505 510 ATG AAT GCC GAA GCT ATT AAA AAG ATT ATT ATG AAA GGC GCA GGG TCT 1584 Met Asn Ala Glu Ala He Lys Lys He He Met Lys Gly Ala Gly Ser 515 520 525 TGT TCA ACT AAA CCA GAA GTT GAA CGA TAT GTT AAG TTC AGT GAT GAT 1632 Cys Ser Thr Lys Pro Glu Val Glu Arg Tyr Val Lys Phe Ser Asp Asp 530 535 540 TTC TTA AAT GAA CTA TCG AAT TAC ACC GAA TCT GTT CTC AAT AGT CTG 1680 Phe Leu Asn Gtu Leu Ser Asn Tyr Thr Glu Ser Val Leu Asn Ser Leu 545 550 555 560 ATT GAA GAA TGT GAA AAA GCA GCT ACA CTT GCT AAT ACA AAT CAG CTG 1728 He Glu Glu Cys Glu Lys Ala Ala Thr Leu Ala Asn Thr Asn Gin Leu 565 570 575 AAC CGT AAA ATT CTC ATT AAC AGT CTT TAT GGT GCT CTT GGT AAT ATT 1776 Asn Arg Lys He Leu He Asn Ser Leu Tyr Gly Ala Leu Gly Asn He 580 585 590 CAT TTC CGT TAC TAT GAT TTG CGA AAT GCT ACT GCT ATC ACA ATT TTC 1824 His Phe Arg Tyr Tyr Asp Leu Arg Asn Ala Thr Ala He Thr He Phe 595 600 605 GGC CAA GTC GGT ATT CAG TGG ATT GCT CGT AAA ATT AAT GAA TAT CTG 1872 Gly Gin Val Gly He Gin Trp He Ala Arg Lys He Asn Glu Tyr Leu 610 615 620 AAT AAA GTA TGC GGA ACT AAT GAT GAA GAT TTC ATT GCA GCA GGT GAT 1920 Asn Lys Val Cys Gly Thr Asn Asp Glu Asp Phe He Ata Ala Gty Asp 625 630 635 640 ACT GAT TCG GTA TAT GTT TGC GTA GAT AAA GTT ATT GAA AAA GTT GGT 1968 Thr Asp Ser Vat Tyr Val Cys Val Asp Lys Val He Glu Lys Val Gly 645 650 655 CTT GAC CGA TTC AAA GAG CAG AAC GAT TTG GTT GAA TTC ATG AAT CAG 2016 Leu Asp Arg Phe Lys Glu Gin Asn Asp Leu Val Glu Phe Met Asn Gin 660 665 670 TTC GGT AAG AAA AAG ATG GAA CCT ATG ATT GAT GTT GCA TAT CGT GAG 2064 Phe Gly Lys Lys Lys Met Glu Pro Met He Asp Vat Ala Tyr Arg Glu 675 680 685 TTA TGT GAT TAT ATG AAT AAC CGC GAG CAT CTG ATG CAT ATG GAC CGT 2112 Leu Cys Asp Tyr Met Asn Asn Arg Glu His Leu Met His Met Asp Arg 690 695 700 GAA GCT ATT TCT TGC CCT CCG CTT GGT TCA AAG GGC GTT GGT GGA TTT 2160 Glu Ala He Ser Cys Pro Pro Leu Gly Ser Lys Gly Vat Gly Gly Phe 705 710 715 720 TGG AAA GCG AAA AAG CGT TAT GCT CTG AAC GTT TAT GAT ATG GAA GAT 2208 Trp Lys Ala Lys Lys Arg Tyr Ala Leu Asn Val Tyr Asp Met Glu Asp 725 730 735 AAG CGA TTT GCT GAA CCG CAT CTA AAA ATC ATG GGT ATG GAA ACT CAG 2256 Lys Arg Phe Ala Glu Pro His Leu Lys He Met Gly Met Gtu Thr Gin 740 745 750 CAG AGT TCA ACA CCA AAA GCA GTG CAA GAA GCT CTC GAA GAA AGT ATT 2304 Gin Ser Ser Thr Pro Lys Ala Val Gin Glu Ala Leu Glu Glu Ser He 755 760 765 CGT CGT ATT CTT CAG GAA GGT GAA GAG TCT GTC CAA GAA TAC TAC AAG 2352 Arg Arg He Leu Gin Glu Gly Glu Glu Ser Val Gin Gtu Tyr Tyr Lys 770 775 780 AAC TTC GAG AAA GAA TAT CGT CAA CTT GAC TAT AAA GTT ATT GCT GAA 2400 Asn Phe Glu Lys Glu Tyr Arg Gin Leu Asp Tyr Lys Val He Ala Glu 785 790 795 800 GTA AAA ACT GCG AAC GAT ATA GCG AAA TAT GAT GAT AAA GGT TGG CCA 2448 Val Lys Thr Ala Asn Asp He Ala Lys Tyr Asp Asp Lys Gly Trp Pro 805 810 815 GGA TTT AAA TGC CCG TTC CAT ATT CGT GGT GTG CTA ACT TAT CGT CGA 2496 Gly Phe Lys Cys Pro Phe His He Arg Gty Val Leu Thr Tyr Arg Arg 820 825 830 GCT GTT AGC GGT TTA GGT GTA GCT CCA ATT TTG GAT GGA AAT AAA GTA 2544 Ala Val Ser Gly Leu Gly Val Ala Pro He Leu Asp Gly Asn Lys Val 835 840 845 ATG GTT CTT CCA TTA CGT GAA GGA AAT CCA TTT GGT GAC AAG TGC ATT 2592 Met Val Leu Pro Leu Arg Glu Gly Asn Pro Phe Gly Asp Lys Cys He 850 855 860 GCT TGG CCA TCG GGT ACA GAA CTT CCA AAA GAA ATT CGT TCT GAT GTG 2640 Ala Trp Pro Ser Gly Thr Glu Leu Pro Lys Glu He Arg Ser Asp Val 865 870 875 880 CTA TCT TGG ATT GAC CAC TCA ACT TTG TTC CAA AAA TCG TTT GTT AAA 2688 Leu Ser Trp He Asp His Ser Thr Leu Phe Gin Lys Ser Phe Val Lys 885 890 895 CCG CTT GCG GGT ATG TGT GAA TCG GCT GGC ATG GAC TAT GAA GAA AAA 2736 Pro Leu Ala Gly Met Cys Glu Ser Ala Gty Met Asp Tyr Glu Glu Lys 900 905 910 GCT TCG TTA GAC TTC CTG TTT GGC 2760 Ala Ser Leu Asp Phe Leu Phe Gly 915 920 (2) INFORMATION FOR SEQ ID NO:4: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 920 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: protein (Xi) SEQUENCE DESCRIPTION: SEQ ID NO:4: Arg His Leu His Phe Phe Phe Phe Phe Phe Phe Phe Phe Phe Phe Phe 1 5 10 15 Phe Phe Phe Phe He He Met Lys Glu Phe Tyr He Ser He Glu Thr 20 25 30 Val Gly Asn Asn He Val Glu Arg Tyr He Asp Glu Asn Gly Lys Glu 35 40 45 Arg Thr Arg Glu Val Glu Tyr Leu Pro Thr Met Phe Arg His Cys Lys 50 55 60 Glu Glu Ser Lys Tyr Lys Asp He Tyr Gly Lys Asn Cys Ala Pro Gin 65 70 75 80 Lys Phe Pro Ser Met Lys Asp Ala Arg Asp Trp Met Lys Arg Met Glu 85 90 95 Asp He Gty Leu Glu Ala Leu Gly Met Asn Asp Phe Lys Leu Ala Tyr 100 105 110 He Ser Asp Thr Tyr Gly Ser Glu He Val Tyr Asp Arg Lys Phe Val 115 120 125 Arg Val Ala Asn Cys Asp He Glu Val Thr Gly Asp Lys Phe Pro Asp 130 135 140 Pro Met Lys Ala Gtu Tyr Glu He Asp Ata He Thr His Tyr Asp Ser 145 150 155 160 He Asp Asp Arg Phe Tyr Val Phe Asp Leu Leu Asn Ser Met Tyr Gly 165 170 175 Ser Val Ser Lys Trp Asp Ala Lys Leu Ala Ala Lys Leu Asp Cys Glu 180 185 190 Gty Gly Asp Glu Val Pro Gin Glu He Leu Asp Arg Val He Tyr Met 195 200 205 Pro Phe Asp Asn Glu Arg Asp Met Leu Met Glu Tyr He Asn Leu Trp 210 215 220 Glu Gin Lys Arg Pro Ala He Phe Thr Gly Trp Asn He Glu Gly Phe 225 230 235 240 Asp Val Pro Tyr He Met Asn Arg Val Lys Met He Leu Gly Glu Arg 245 250 255 Ser Met Lys Arg Phe Ser Pro He Gly Arg Val Lys Ser Lys Leu He 260 265 270 Gtn Asn Met Tyr Gly Ser Lys Glu He Tyr Ser He Asp Gly Val Ser 275 280 285 He Leu Asp Tyr Leu Asp Leu Tyr Lys Lys Phe Ala Phe Thr Asn Leu 290 295 300 Pro Ser Phe Ser Leu Glu Ser Val Ala Gin His Gtu Thr Lys Lys Gly 305 310 315 320 Lys Leu Pro Tyr Asp Gly Pro He Asn Lys Leu Arg Glu Thr Asn His 325 330 335 Gin Arg Tyr He Ser Tyr Asn He He Asp Val Gtu Ser Val Gin Ala 340 345 350 He Asp Lys He Arg Gly Phe He Asp Leu Val Leu Ser Met Ser Tyr 355 360 365 Tyr Ala Lys Met Pro Phe Ser Gly Val Met Ser Pro He Lys Thr Trp 370 375 380 Asp Ala He He Phe Asn Ser Leu Lys Gly Glu His Lys Val He Pro 385 390 395 400 Gin Gin Gly Ser His Val Lys Gin Ser Phe Pro Gly Ala Phe Val Phe 405 410 415 Glu Pro Lys Pro He Ala Arg Arg Tyr He Met Ser Phe Asp Leu Thr 420 425 430 Ser Leu Tyr Pro Ser He He Arg Gin Val Asn He Ser Pro Glu Thr 435 440 445 He Arg Gly Gin Phe Lys Val His Pro He His Glu Tyr He Ala Gly 450 455 . 460 Thr Ala Pro Lys Pro Ser Asp Glu Tyr Ser Cys Ser Pro Asn Gly Trp 465 470 475 480 Met Tyr Asp Lys His Gin Glu Gly He He Pro Lys Glu He Ala Lys 485 490 495 Val Phe Phe Gin Arg Lys Asp Trp Lys Lys Lys Met Phe Ala Glu Glu 500 505 510 Met Asn Ala Glu Ala He Lys Lys He He Met Lys Gly Ala Gly Ser 515 520 525 Cys Ser Thr Lys Pro Glu Val Glu Arg Tyr Val Lys Phe Ser Asp Asp 530 535 540 Phe Leu Asn Glu Leu Ser Asn Tyr Thr Gtu Ser Val Leu Asn Ser Leu 545 550 555 560 He Glu Glu Cys Glu Lys Ala Ala Thr Leu Ala Asn Thr Asn Gin Leu 565 570 575 Asn Arg Lys He Leu He Asn Ser Leu Tyr Gly Ala Leu Gly Asn He 580 585 590 His Phe Arg Tyr Tyr Asp Leu Arg Asn Ala Thr Ala He Thr He Phe 595 600 605 Gly Gin Val Gly He Gin Trp He Ala Arg Lys He Asn Glu Tyr Leu 610 615 620 Asn Lys Val Cys Gly Thr Asn Asp Glu Asp Phe He Ala Ala Gly Asp 625 630 635 640 Thr Asp Ser Val Tyr Val Cys Val Asp Lys Val He Glu Lys Val Gly 645 650 655 Leu Asp Arg Phe Lys Glu Gin Asn Asp Leu Val Glu Phe Met Asn Gin 660 665 670 Phe Gly Lys Lys Lys Met Gtu Pro Met He Asp Val Ala Tyr Arg Glu 675 680 685 Leu Cys Asp Tyr Met Asn Asn Arg Glu His Leu Met His Met Asp Arg 690 695 700 Glu Ala He Ser Cys Pro Pro Leu Gly Ser Lys Gly Val Gly Gly Phe 705 710 715 720 Trp Lys Ala Lys Lys Arg Tyr Ala Leu Asn Vat Tyr Asp Met Gtu Asp 725 730 735 Lys Arg Phe Ala Glu Pro His Leu Lys He Met Gly Met Glu Thr Gin 740 745 750 Gin Ser Ser Thr Pro Lys Ala Val Gin Glu Ala Leu Glu Glu Ser He 755 760 765 Arg Arg He Leu Gin Glu Gly Glu Glu Ser Val Gin Glu Tyr Tyr Lys 770 775 780 Asn Phe Gtu Lys Glu Tyr Arg Gin Leu Asp Tyr Lys Val He Ala Glu 785 790 795 800 Val Lys Thr Ala Asn Asp He Ala Lys Tyr Asp Asp Lys Gly Trp Pro 805 810 815 Gly Phe Lys Cys Pro Phe His He Arg Gly Val Leu Thr Tyr Arg Arg 820 825 830 Ala Val Ser Gly Leu Gly Val Ala Pro He Leu Asp Gly Asn Lys Val 835 840 845 . Met Vat Leu Pro Leu Arg Glu Gly Asn Pro Phe Gty Asp Lys Cys He 850 855 860 Ala Trp Pro Ser Gty Thr Glu Leu Pro Lys Glu He Arg Ser Asp Val 865 870 875 880 Leu Ser Trp He Asp His Ser Thr Leu Phe Gin Lys Ser Phe Val Lys 885 890 895 Pro Leu Ala Gly Met Cys Glu Ser Ala Gly Met Asp Tyr Glu Glu Lys 900 905 910 Ala Ser Leu Asp Phe Leu Phe Gty 915 920 (2) INFORMATION FOR SEQ ID N0:5: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 2459 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: DNA (genomic) (ix) FEATURE: (A) NAME/KEY: CDS (B) LOCATION: 108..2456 (xi) SEQUENCE DESCRIPTION: SEQ ID NO:5: AAGCATGGCG CGAAGGCATA TTACGGGCAG TAATGACTGT ATAAAACCAC AGCCAATCAA 60 ACGAAACCAG GCTATACTCA AGCCTGGTTT TTTGATGGAT TTTCAGC GTG GCG CAG 116 Val Ala Gin 1 GCA GGT TTT ATC TTA ACC CGA CAC TGG CGG GAC ACC CCG CAA GGG ACA 164 Ala Gly Phe He Leu Thr Arg His Trp Arg Asp Thr Pro Gin Gly Thr 5 10 15 GAA GTC TCC TTC TGG CTG GCG ACG GAC AAC GGG CCG TTG CAG GTT ACG 212 Glu Val Ser Phe Trp Leu Ala Thr Asp Asn Gly Pro Leu Gin Vat Thr 20 25 30 35 CTT GCA CCG CAA GAG TCC GTG GCG TTT ATT CCC GCC GAT CAG GTT CCC 260 Leu Ala Pro Gin Glu Ser Val Ala Phe He Pro Ala Asp Gin Vat Pro 40 45 50 CGC GCT CAG CAT ATT TTG CAG GGT GAA CAA GGC TTT CGC CTG ACA CCG 308 Arg Ala Gin His He Leu Gin Gly Glu Gin Gly Phe Arg Leu Thr Pro 55 60 65 CTG GCG TTA AAG GAT TTT CAC CGC CAG CCG GTG TAT GGC CTT TAC TGT 356 Leu Ala Leu Lys Asp Phe His Arg Gin Pro Vat Tyr Gly Leu Tyr Cys 70 75 80 CGC GCC CAT CGC CAA TTG ATG AAT TAC GAA AAG CGC CTG CGT GAA GGT 404 Arg Ala His Arg Gin Leu Met Asn Tyr Glu Lys Arg Leu Arg Glu Gly 85 90 95 GGC GTT ACC GTC TAC GAG GCC GAT GTG CGT CCG CCA GAA CGC TAT CTG 452 Gly Val Thr Val Tyr Glu Ala Asp Val Arg Pro Pro Glu Arg Tyr Leu 100 105 110 115 ATG GAG CGG TTT ATC ACC TCA CCG GTG TGG GTC GAG GGT GAT ATG CAC 500 Met Glu Arg Phe He Thr Ser Pro Val Trp Val Glu Gly Asp Met His 120 125 130 AAT GGC ACT ATC GTT AAT GCC CGT CTG AAA CCG CAT CCC GAC TAT CGT 548 Asn Gly Thr He Val Asn Ala Arg Leu Lys Pro His Pro Asp Tyr Arg 135 140 145 CCG CCG CTC AAG TGG GTT TCT ATA GAT ATT GAA ACC ACC CGC CAC GGT 596 Pro Pro Leu Lys Trp Val Ser He Asp He Glu Thr Thr Arg His Gly 150 155 160 GAG CTG TAC TGC ATC GGC CTG GAA GGC TGC GGG CAG CGC ATC GTT TAT 644 Glu Leu Tyr Cys He Gly Leu Glu Gly Cys Gly Gin Arg He Val Tyr 165 170 175 ATG CTG GGG CCG GAG AAT GGC GAC GCC TCC TCG CTT GAT TTC GAA CTG 692 Met Leu Gty Pro Glu Asn Gly Asp Ala Ser Ser Leu Asp Phe Glu Leu 180 185 190 195 GAA TAC GTC GCC AGC CGC CCG CAG TTG CTG GAA AAA CTC AAC GCC TGG 740 Glu Tyr Val Ala Ser Arg Pro Gin Leu Leu Glu Lys Leu Asn Ala Trp 200 205 210 TTT GCC AAC TAC GAT CCT GAT GTG ATC ATC GGT TGG AAC GTG GTG CAG 788 Phe Ala Asn Tyr Asp Pro Asp Val He He Gly Trp Asn Val Val Gin 215 220 225 TTC GAT CTG CGA ATG CTG CAA AAA CAT GCC GAG CGT TAC CGT CTT CCG 836 Phe Asp Leu Arg Met Leu Gin Lys His Ala Gtu Arg Tyr Arg Leu Pro 230 235 240 CTG CGT CTT GGG CGC GAT AAT AGC GAG CTG GAG TGG CGC GAC GAC GGC 884 Leu Arg Leu Gly Arg Asp Asn Ser Glu Leu Gtu Trp Arg Asp Asp Gly 245 250 255 TTT AAA AAC GGC GTC TTT TTT GCC CAG GCT AAA GGT GGG CTA ATT ATC 932 Phe Lys Asn Gly Val Phe Phe Ala Gin Ala Lys Gly Gly Leu He He 260 265 270 275 GAC GGT ATC GAG GCG CTG AAA TCC GCG TTC TGG AAT TTC TCT TCA TTC 980 Asp Gly He Glu Ala Leu Lys Ser Ala Phe Trp Asn Phe Ser Ser Phe 280 285 290 TCG CTG GAA ACT GTC GCT CAG GAG CTA TTA GGC GAA GGA AAA TCT ATC 1028 Ser Leu Glu Thr Val Ala Gin Gtu Leu Leu Gly Glu Gly Lys Ser He 295 300 305 GAT AAC CCG TGG GAT CGA ATG GAC GAA ATT GAC CGC CGT TTC GCC GAA 1076 Asp Asn Pro Trp Asp Arg Met Asp Glu He Asp Arg Arg Phe Ala Glu 310 315 320 GAT AAA CCT GCG CTG GCA ACT TAT AAC CTG AAA GAT TGC GAG CTG GTG 1124 Asp Lys Pro Ata Leu Ala Thr Tyr Asn Leu Lys Asp Cys Glu Leu Val 325 330 335 ACG CAG ATC TTC CAC AAA ACT GAA ATC ATG CCA TTT TTA CTC GAA CGG 1172 Thr Gin He Phe His Lys Thr Glu He Met Pro Phe Leu Leu Gtu Arg 340 345 350 355 GCA ACG GTG AAC GGC CTG CCG GTG GAC CGA CAC GGC GGT TCG GTG GCG 1220 Ala Thr Val Asn Gly Leu Pro Val Asp Arg His Gly Gty Ser Val Ala 360 365 370 GCA TTT GGT CAT CTC TAT TTT CCG CGA ATG CAT CGC GCT GGT TAT GTC 1268 Ala Phe Gly His Leu Tyr Phe Pro Arg Met His Arg Ala Gty Tyr Val 375 380 385 GCG CCT AAT CTC GGC GAA GTG CCG CCG CAC GCC AGC CCT GGC GGC TAC 1316 Ala Pro Asn Leu Gly Glu Val Pro Pro His Ala Ser Pro Gly Gly Tyr 390 395 400 GTG ATG GAT TCA CGG CCA GGG CTT TAT GAT TCA GTG CTG GTG CTG GAC 1364 Val Met Asp Ser Arg Pro Gly Leu Tyr Asp Ser Val Leu Val Leu Asp 405 410 415 TAT AAA AGC CTG TAC CCG TCG ATC ATC CGC ACC TTT CTG ATT GAT CCC 1412 Tyr Lys Ser Leu Tyr Pro Ser He He Arg Thr Phe Leu He Asp Pro 420 425 430 435 GTC GGG CTG GTG GAA GGC ATG GCG CAG CCT GAT CCA GAG CAC AGT ACC 1460 Val Gly Leu Val Glu Gly Met Ala Gin Pro Asp Pro Glu His Ser Thr 440 445 450 GAA GGT TTT CTC GAT GCC TGG TTC TCG CGA GAA AAA CAT TGC CTG CCG 1508 Glu Gly Phe Leu Asp Ala Trp Phe Ser Arg Glu Lys His Cys Leu Pro 455 460 465 GAG ATT GTG ACT AAC ATC TGG CAC GGG CGC GAT GAA GCC AAA CGC CAG 1556 Glu He Val Thr Asn He Trp His Gly Arg Asp Glu Ala Lys Arg Gin 470 475 480 GGT AAC AAA CCG CTG TCG CAG GCG CTG AAA ATC ATC ATG AAT GCC TTT 1604 Gly Asn Lys Pro Leu Ser Gin Ala Leu Lys He He Met Asn Ala Phe 485 490 495 TAT GGC GTG CTC GGC ACC ACC GCC TGC CGC TTC TTC GAT CCG CGG CTG 1652 Tyr Gly Val Leu Gly Thr Thr Ala Cys Arg Phe Phe Asp Pro Arg Leu 500 505 510 515 GCA TCG TCG ATC ACC ATG CGT GGT CAT CAG ATC ATG CGG CAA ACC AAA 1700 Ala Ser Ser He Thr Met Arg Gly His Gin He Met Arg Gin Thr Lys 520 525 530 GCG TTG ATT GAA GCA CAG GGC TAC GAC GTT ATC TAC GGC GAT ACC GAC 1748 Ala Leu He Glu Ala Gin Gly Tyr Asp Val He Tyr Gly Asp Thr Asp 535 540 545 TCA ACG TTT GTC TGG CTG AAA GGC GCA CAT TCG GAA GAA GAA GCG GCG 1796 Ser Thr Phe Val Trp Leu Lys Gly Ala His Ser Glu Glu Glu Ala Ata 550 555 560 AAA ATC GGT CGT GCA CTG GTG CAG CAC GTT AAC GCC TGG TGG GCG GAA 1844 Lys He Gly Arg Ala Leu Vat Gin His Val Asn Ala Trp Trp Ala Glu 565 570 575 ACG CTG CAA AAA CAA CGG CTG ACC AGC GCA TTA GAA CTG GAG TAT GAA 1892 Thr Leu Gin Lys Gin Arg Leu Thr Ser Ala Leu Glu Leu Glu Tyr Glu 580 585 590 595 ACC CAT TTC TGC CGT TTT CTG ATG CCA ACC ATT CGC GGA GCC GAT ACC 1940 Thr His Phe Cys Arg Phe Leu Met Pro Thr He Arg Gly Ala Asp Thr 600 605 610 GGC AGT AAA AAG CGT TAT GCC GGA CTG ATT CAG GAG GGC GAC AAG CAG 1988 Gly Ser Lys Lys Arg Tyr Ala Gly Leu He Gin Glu Gly Asp Lys Gin 615 620 625 CGG ATG GTG TTT AAA GGG CTG GAA ACC GTG CGC ACC GAC TGG ACG CCG 2036 Arg Met Val Phe Lys Gty Leu Glu Thr Val Arg Thr Asp Trp Thr Pro 630 635 640 CTG GCC CAG CAG TTT CAG CAG GAG CTA TAC CTG CGC ATC TTC CGC AAC 2084 Leu Ala Gin Gin Phe Gin Gin Glu Leu Tyr Leu Arg He Phe Arg Asn 645 650 655 GAG CCA TAT CAG GAA TAT GTA CGC GAA ACC ATC GAC AAA CTG ATG GCG 2132 Glu Pro Tyr Gin Glu Tyr Val Arg Glu Thr He Asp Lys Leu Met Ala 660 665 670 675 GGT GAA CTG GAT GCG CGA CTG GTT TAC CGT AAA CGC CTT CGC CGT CCG 2180 Gty Glu Leu Asp Ala Arg Leu Vat Tyr Arg Lys Arg Leu Arg Arg Pro 680 685 690 CTG AGC GAG TAT CAG CGT AAT GTG CCG CCT CAT GTA CGC GCC GCT CGC 2228 Leu Ser Glu Tyr Gin Arg Asn Val Pro Pro His Vat Arg Ala Ala Arg 695 700 705 CTT GCC GAT GAA GAA AAC CAA AAG CGT GGT CGC CCC TTG CAA TAT CAG 2276 Leu Ala Asp Glu Glu Asn Gin Lys Arg Gty Arg Pro Leu Gin Tyr Gin 710 715 720 AAT CGC GGC ACC ATT AAG TAC GTA TGG ACC ACC AAC GGC CCG GAG CCG 2324 Asn Arg Gly Thr He Lys Tyr Val Trp Thr Thr Asn Gly Pro Glu Pro 725 730 735 CTG GAC TAC CAA CGT TCA CCA CTG GAT TAC GAA CAC TAT CTG ACC CGC 2372 Leu Asp Tyr Gin Arg Ser Pro Leu Asp Tyr Glu His Tyr Leu Thr Arg 740 745 750 755 CAG CTA CAA CCC GTG GCG GAG GGA ATA CTC CCT TTT ATT GAG GAT AAT 2420 Gin Leu Gin Pro Val Ala Glu Gly He Leu Pro Phe He Glu Asp Asn 760 765 770 TTT GCT ACA CTT ATG ACC GGG CAA CTT GGG CTA TTT TGA 2459 Phe Ala Thr Leu Met Thr Gly Gin Leu Gly Leu Phe 775 780 (2) INFORMATION FOR SEQ ID NO:6: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 783 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: protein (xi) SEQUENCE DESCRIPTION: SEQ ID N0:6: Val Ala Gin Ala Gly Phe He Leu Thr Arg His Trp Arg Asp Thr Pro 1 5 10 15 Gin Gly Thr Glu Val Ser Phe Trp Leu Ala Thr Asp Asn Gly Pro Leu 20 25 30 Gin Val Thr Leu Ala Pro Gin Glu Ser Vat Ala Phe He Pro Ala Asp 35 40 45 Gin Val Pro Arg Ala Gin His He Leu Gin Gly Glu Gin Gly Phe Arg 50 55 60 Leu Thr Pro Leu Ala Leu Lys Asp Phe His Arg Gin Pro Val Tyr Gly 65 70 75 80 Leu Tyr Cys Arg Ala His Arg Gin Leu Met Asn Tyr Glu Lys Arg Leu 85 90 95 Arg Glu Gly Gty Val Thr Val Tyr Glu Ala Asp Val Arg Pro Pro Glu 100 105 110 Arg Tyr Leu Met Glu Arg Phe He Thr Ser Pro Vat Trp Val Glu Gly 115 120 125 Asp Met His Asn Gly Thr He Val Asn Ala Arg Leu Lys Pro His Pro 130 135 140 Asp Tyr Arg Pro Pro Leu Lys Trp Val Ser He Asp He Glu Thr Thr 145 150 155 160 Arg His Gly Gtu Leu Tyr Cys He Gly Leu Glu Gly Cys Gly Gin Arg 165 170 175 He Vat Tyr Met Leu Gly Pro Glu Asn Gly Asp Ala Ser Ser Leu Asp 180 185 190 Phe Glu Leu Glu Tyr Val Ala Ser Arg Pro Gin Leu Leu Glu Lys Leu 195 200 205 Asn Ala Trp Phe Ala Asn Tyr Asp Pro Asp Val He He Gly Trp Asn 210 215 220 Val Val Gin Phe Asp Leu Arg Met Leu Gin Lys His Ala Glu Arg Tyr 225 230 235 240 Arg Leu Pro Leu Arg Leu Gly Arg Asp Asn Ser Glu Leu Glu Trp Arg 245 250 255 Asp Asp Gly Phe Lys Asn Gly Val Phe Phe Ala Gin Ala Lys Gly Gly 260 265 270 Leu He He Asp Gly He Glu Ala Leu Lys Ser Ala Phe Trp Asn Phe 275 280 285 Ser Ser Phe Ser Leu Glu Thr Val Ala Gin Glu Leu Leu Gly Glu Gly 290 295 300 Lys Ser He Asp Asn Pro Trp Asp Arg Met Asp Glu He Asp Arg Arg 305 310 315 320 Phe Ala Glu Asp Lys Pro Ala Leu Ala Thr Tyr Asn Leu Lys Asp Cys 325 330 335 Glu Leu Val Thr Gin He Phe His Lys Thr Glu He Met Pro Phe Leu 340 345 350 Leu Glu Arg Ala Thr Val Asn Gty Leu Pro Val Asp Arg His Gly Gly 355 360 365 Ser Val Ala Ala Phe Gly His Leu Tyr Phe Pro Arg Met His Arg Ala 370 375 380 Gly Tyr Val Ala Pro Asn Leu Gty Glu Val Pro Pro His Ala Ser Pro 385 390 395 400 Gly Gty Tyr Val Met Asp Ser Arg Pro Gly Leu Tyr Asp Ser Val Leu 405 410 415 Val Leu Asp Tyr Lys Ser Leu Tyr Pro Ser He He Arg Thr Phe Leu 420 425 430 He Asp Pro Val Gty Leu Val Glu Gly Met Ala Gin Pro Asp Pro Glu 435 440 445 His Ser Thr Glu Gly Phe Leu Asp Ala Trp Phe Ser Arg Glu Lys His 450 455 460 Cys Leu Pro Glu He Val Thr Asn He Trp His Gly Arg Asp Glu Ala 465 470 475 480 Lys Arg Gin Gty Asn Lys Pro Leu Ser Gin Ala Leu Lys He He Met 485 490 495 Asn Ala Phe Tyr Gly Val Leu Gly Thr Thr Ala Cys Arg Phe Phe Asp 500 505 510 Pro Arg Leu Ala Ser Ser He Thr Met Arg Gly His Gin He Met Arg 515 520 525 Gin Thr Lys Ala Leu He Glu Ala Gin Gly Tyr Asp Val He Tyr Gly 530 535 540 Asp Thr Asp Ser Thr Phe Val Trp Leu Lys Gly Ala His Ser Glu Glu 545 550 555 560 Glu Ala Ala Lys He Gty Arg Ala Leu Val Gin His Val Asn Ala Trp 565 570 575 Trp Ala Glu Thr Leu Gin Lys Gin Arg Leu Thr Ser Ata Leu Glu Leu 580 585 590 Glu Tyr Glu Thr His Phe Cys Arg Phe Leu Met Pro Thr He Arg Gly 595 600 605 Ala Asp Thr Gty Ser Lys Lys Arg Tyr Ala Gly Leu He Gin Glu Gly 610 615 620 Asp Lys Gin Arg Met Val Phe Lys Gly Leu Glu Thr Val Arg Thr Asp 625 630 635 640 Trp Thr Pro Leu Ala Gin Gin Phe Gin Gin Glu Leu Tyr Leu Arg He 645 650 655 Phe Arg Asn Glu Pro Tyr Gin Glu Tyr Val Arg Glu Thr He Asp Lys 660 665 670 Leu Met Ala Gly Glu Leu Asp Ala Arg Leu Val Tyr Arg Lys Arg Leu 675 680 685 Arg Arg Pro Leu Ser Glu Tyr Gin Arg Asn Val Pro Pro His Val Arg 690 695 700 Ala Ala Arg Leu Ala Asp Glu Glu Asn Gin Lys Arg Gly Arg Pro Leu 705 710 715 720 Gin Tyr Gin Asn Arg Gly Thr He Lys Tyr Val Trp Thr Thr Asn Gly 725 730 735 Pro Gtu Pro Leu Asp Tyr Gin Arg Ser Pro Leu Asp Tyr Gtu His Tyr 740 745 750 Leu Thr Arg Gin Leu Gin Pro Val Ala Glu Gly He Leu Pro Phe He 755 760 765 Glu Asp Asn Phe Ala Thr Leu Met Thr Gly Gin Leu Gly Leu Phe 770 775 780

Claims: WHAT IS CLAIMED IS: 1. A variant family B DNA polymerase characterized in that it has no 3'→5' exonuclease activity. 2. The variant family B DNA polymerase of claim 1 wherein said polymerase is selected from the group consisting of variant T4 DNA polymerase, variant E. Coli DNA polymerase II, variant T2 DNA polymerase and variant T6 DNA polymerase. 3. The variant family B DNA polymerase of claim 2 wherein said variant T4 DNA polymerase is characterized in that the isoleucine present at condon position 50 is replaced with leucine. 4. The variant family B DNA polymerase of claim 2 wherein said variant T4 DNA polymerase is characterized in that the glutamic acid present at codon position 82 is replaced with aspartic acid. 5. The variant family B DNA polymerase of claim 2 wherein said variant T4 DNA polymerase is characterized in that the tryptophan present at codon position 213 is replaced with serine. 6. The variant family B DNA polymerase of claim 2 wherein said variant T4 DNA polymerase is characterized in that the glutamic acid present at condon position 255 is replaced with serine. 7. The variant family B DNA polymerase of claim 2 wherein said variant T4 DNA polymerase is characterized in that the isoleucine present at condon position 417 is replaced with valine. 8. The variant family B DNA polymerase of claim 2 wherein said variant T4 DNA polymerase is characterized in that the alanine present at condon position 737 is replaced with valine. 9. The variant family B DNA polymerase of claim 2 wherein said variant T4 DNA polymerase is characterized in that the alanine present at condon position 743 is replaced with valine. 10. The variant family B DNA polymerase of claim 2 wherein said variant T4 DNA polymerase is characterized in that the aspartic acid present at condon position 112 is replaced with alanine. 11. The variant family B DNA polymerase of claim 2 wherein said variant T4 DNA polymerase is characterized in that the isoleucine present at condon position 114 is replaced with leucine. 12. The variant family B DNA polymerase of claim 2 wherein said variant T4 DNA polymerase is characterized in that the aspartic acid present at condon position 219 is replaced with alanine. 13. The variant family B DNA polymerase of claim 2 wherein said variant T4 DNA polymerase is characterized in that the aspartic acid present at condon position 324 is replaced with alanine. 14. The variant family B DNA polymerase of claim 2 wherein said variant E. coli DNA polymerase II is characterized in that the aspartic acid present at condon position 156 is replaced with alanine. 15. The variant family B DNA polymerase of claim 2 wherein said variant E. coli DNA polymerase II is characterized in that the glutamic acid present at condon position 158 is replaced with alanine. 16. A method for sequencing DNA comprising the steps of: contacting a polymerase with a primed DNA strand to be sequenced in the presence of dATP, dGTP, dCTP, dTTP and a first chain-terminating nucleotide selected from the group consisting of ddATP and 3'-amino-2',3'dideoxy-ATP, a second chain-terminating nucleotide selected from the group consisting of ddGTP and 3'-amino-2',3'-dideoxy-GTP, a third chain-terminating nucleotide selected from the group consisting of araCTP and 3'-amino,2',3'dideoxy-CTP and a fourth chain- terminating nucleotide selected from the group consisting of araUTP and 3'-amino- 2',3'dideoxy-TTP, and allowing said contacting to proceed under reaction conditions to maintain polymerase activity for a period of time sufficient to obtain sequencing information. 17. The method of claim 16 wherein said first chain-terminating nucleotide is ddATP, said second chain-terminating nucleotide is ddGTP, said third chain- terminating nucleotide is araCTP, and said fourth chain-terminating nucleotide is araUTP. 18. The method of claim 17 wherein the polymerase is selected from the group consisting of variant T4 polymerase, variant E. coli DNA polymerase II, variant T2 polymerase and variant T6 polymerase. 19. The method of claim 18 wherein the polymerase is variant T4 polymerase. 20. The method of claim 19 further comprising at least one accessory protein which forms a complex with said variant T4 polymerase thereby increasing the processivity of said variant T4 polymerase. 21. The method of claim 20 wherein the accessory protein is selected from the group consisting of T4 gene products 32, 41, 45 and the 44/62 complex. 22. The method of claim 18 wherein the variant polymerase is variant R . coli DNA polymerase II. 23. The method of claim 22 further comprising at least one accessory protein which forms a complex with the variant E. coli DNA polymerase II thereby increasing the processivity of said variant E. coli DNA polymerase II. 24. The method of claim 23 wherein said accessory protein is the combination of β protein, γ complex, and SSB protein. 25. The method of claim 16 wherein said first chain-terminating nucleotide is 3'-amino-2',3'dideoxy-ATP, said second chain-terminating nucleotide is 3'-amino- 2',3'dideoxy-GTP, said third chain-terminating nucleotide is 3'-amino-2',3'dideoxy- CTP, and said fourth chain-terminating nucleotide is 3'-amino-2',3'dideoxy-TTP. 26. The method of claim 25 wherein the polymerase is selected from the group consisting of T4 polymerase, variant T4 polymerase, E. coli DNA polymerase II, variant E. coli DNA polymerase II, T2 polymerase, variant T2 polymerase, T6 polymerase and variant T6 polymerase. 27. The method of claim 26 wherein the polymerase is selected from the group consisting of T4 polymerase and variant T4 polymerase. 28. The method of claim 27 further comprising at least one accessory protein which forms a complex with T4 polymerase or variant T4 polymerase thereby increasing the processivity of said T4 polymerase or variant T4 polymerase. 29. The method of claim 28 wherein the accessory protein is selected from the group consisting of T4 gene products 32, 41, 45 and the 44/62 complex. 30. The method of claim 26 wherein the variant polymerase is E. coli DNA polymerase II and variant E. coli DNA polymerase II. 31. The method of claim 30 further comprising at least one accessory protein which forms a complex with the E. coli DNA polymerase II or variant . coli DNA polymerase II thereby increasing the processivity of said E. coli DNA polymerase II variant E. coli DNA polymerase II. 32. The method of claim 31 wherein said accessory protein is the combination of β protein, γ complex, and SSB protein. 33. A method for sequencing DNA comprising the steps of: contacting a variant T4 DNA polymerase with a primed DNA strand to be sequenced in the presence of standard nucleotides wherein the concentration of one of the standard nucleotides is very low when compared to the concentration of the other standard nucleotides; and allowing said contacting to proceed under reaction conditions to maintain polymerase activity for a period of time sufficient to obtain sequencing information. 34. A method of identifying and isolating variant T4 DNA polymerases comprising the steps of: identifying T4 strains having variant T4 DNA polymerases defective in some aspect of DNA replication; isolating further modified forms of said variant T4 DNA polymerases by selection in an E. coli optAl host; isolating T4 strains which contain variant T4 DNA polymerases having at least one additional mutation which corrects or compensates said defect in DNA replication; identifying the additional correcting/compensating mutation(s) in said variant T4 DNA polymerases; and introducing said identified correcting/compensating mutations(s) T4 DNA polymerases into T4 phage or T4 DNA polymerase expression vectors.

Inventors: GOODMAN MYRON F, REHA-KRANTZ LINDA J, GOODMAN, MYRON, F., REHA-KRANTZ, LINDA, J.
Applicants: UNIV ALBERTA, UNIV SOUTHERN CALIFORNIA, THE GOVERNORS OF THE UNIVERSITY OF ALBERTA, UNIVERSITY OF SOUTHERN CALIFORNIA
Application year: 1994
Main classification: C12Q1
IPC codes: C07H19, C07H21, C12N9, C12N15, C12Q1, C12R1